fn main() {
    println!("==================================");
    //test01_call_panic();
    println!("==================================");
    test02_backtrace();
    println!("==================================");
}

fn test01_call_panic() {
    panic!("crash and burn");
}

fn test02_backtrace() {
    let v = vec![1, 2, 3];
    v[99];
}
